Equipment such as remote radio heads (RRHs) are installed at the top of cell towers. Each RRH requires direct current (DC) to power the RRH. To supply DC, a dedicated DC cable runs directly from the power plant on the ground to the RRH. In order to compensate for voltage drop, a bigger gauge of DC cable is used.
This type of installation is expensive. One reason is that the size and weight of DC cables may require to the tower structure to be modified. Another reason is that DC surge protection is required at tower top to protect against lightning strikes. In general, larger cables with higher current carrying capacity require a higher level of surge protection. Yet another reason is that the DC cables are made of copper, which is expensive because it is prone to theft. Copper theft is expensive not only because of the material and labor costs but also because of the cost of lost service due to a broken site. Lost service has large impacts on networks.
Cellular operators have been hit in the recent years with copper theft. Several towers are located in uninhabited areas and it is easy to extract copper from cables. Operators are responding by adding security gates/wires and by adding surveillance cameras.